Inhalation devices

The variety of A.I. devices for asthma patients is confusing. Here are some facts and a figure.

Historical aspects of inhalation therapyInhalation therapy has been applied for the treatment of cough over thousands of years. Leaves of a plant called Atropa belladonna were smoked in India to reduce coughing. From the end of the 19th century until the 1960s, miners in particular smoked cigarettes filled with dried blossoms and leaves of thorn-apple to reduce symptoms of occupational asthma.

Nebulizers were the devices commonly used for the inhalation of aerosolized drugs from the 19th century until the beginning of the 20th century. With further development compressed air-nebulizers (jet nebulizers) entered the market during the 1930s. In 1955 the first pressurized metered-dose inhaler(pMDI), called Medihaler®, was developed. Ultrasonic nebulizers using high-frequency acoustical energy were introduced in the 1960s. In 1971, the first dry powder inhaler (DPI) known as Spinhaler® was approved for the administration of sodium cromoglycate.
Open-tube spacer devices intended for use with MDIs were developed in the late 1970s.

These spacers and holding chambers allowed the avoidance of coordination and also reduced oropharyngeal deposition of drug.